Present building and design methods are based on an established way of thinking how to design apartments and arrange the space within the building. The apartments are produced as standardized sizes starting from one room unit to as many rooms as needed. After the building is finished, the possibilities to modify dwelling sizes, floor plan, numbers of rooms and room sizes in apartments are rather limited. The amount of modification work required is extensive and the changes are thus expensive. Changing the use of a building or apartments to other uses such as office or shop space or vice versa is difficult and the final outcome of the changes may be less than satisfactory. This results several problems. Wrong kinds of apartments are built in wrong places and demand is not satisfied. Residence areas may get profiled to certain resident profiles, which may deter the desirability of the apartments for other types of residents. Building property can't be optimally utilizes as changes of apartments size and type of use can't be done on basis of demand. One particular problem is that buildings can't be adapted to changes in society and modern housing needs or needs of the tenants. Future demands can't be predicted and thus adaptability would be desirable.
Flexibility in design and construction of buildings can be increased by providing large open spaces that can be divided by light, not load bearing divisioning walls in desired spaces or rooms and apartments. Usually this includes using a vertical duct well for water supply lines, sewers and possibly electric supply lines. Even though these systems provide increased flexibility, they limit location of kitchens, bathrooms and any room requiring sewer connection to the side of these vertical wells in certain areas of already defined flat size. These structures require placement of horizontal ducts and sewers in the floor and often embedding them in the floor structure so that locations of sewers and such is fixed or changing of the location of them requires extensive exposing of ducts within the floor or wall structures. Thus the modifiability of the room space is severely limited. Some examples of known structures are presented in documents CN 1108727, CN110359, JP2009097256, WO04048710 and U.S. Pat. No. 3,710,521.